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This fossil tree was first brought to notice by John MacCulloch in 1819.
It is the cast of a tree over 12m high and a metre and a half in diameter
which, standing upright, was engulfed by lava and has now been exposed
through erosion.
During the Tertiary period, 50-60 million years ago, lava not only erupted
violently from volcanoes, but also flowed more gently out of cracks in
the earth's crust known as dykes. The lava flow that engulfed the tree
must have been quiet enough to leave it in situ. As it cooled in formed
in columns, similar to those seen at Staffa and at right-angles to the
cooling surface - in this case the trunk of the tree which, indeed, exerted
a sufficient drag on the lava flow to leave the columns slightly bent.
The walk out to the tree is not for the faint-hearted but there is interest
every step of the way - the views are magnificent and the assemblage of
geological features is unique. Buzzards and golden eagles range the cliffs
and wild goats browse the talus slopes whilst a look to seaward will very
likely reveal the head of a seal or even an otter.
References:
J MacCulloch, A Description of the Western Islands of Scotland (London
1819) vol i p. 568
Mull in the Making by Rosalind Jones
Olive Brown and Jean Whittaker, Walking in South Mull and Iona (Revised
& expanded ed 1996)
ISBN 0 9528428 0 7
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